Optical fibers may be used to transfer light from an emitting source to a receiver. The light source may transmit data within emitted light to support communication between two ends of the optical fibers. The optical fibers may be protected from scratches and abrasions by a coating that covers the optical fiber's length. The protective coating may be cured via exposing it to a certain wavelength light energy. In one example, the coating cures when it is exposed to ultraviolet (UV) light. The UV light source may be protected from vapors that are emitted during curing of the coating by a curing tube that surrounds the fiber and isolates the fiber from the light source. However, the curing tube may become covered with deposits over time, thereby reducing the amount of light energy that reaches the fiber. One way to reduce deposits in the curing tube may be to periodically replace the curing tube based on the curing tube's time in use. However, if the curing tube is not replaced soon enough, the protective coating may not cure as is desired.
Another way of addressing deposits in a curing tube is described in U.S. Pat. No. 5,418,369. An elliptical reflecting chamber, a UV light bulb, and two UV sensing devices placed outside the elliptical reflecting chamber are described. The first UV sensor monitors an amount of light emitted from the UV bulb, the second UV sensor monitors light passing through a curing tube and an average of light eluding the curing tube is described. However, the elliptical reflecting chamber and light bulb described in U.S. Pat. No. 5,418,369 may not be as efficient as is desired, and the signal to noise ratio for the light detectors may not be at a desirable level.
The inventor herein has recognized the above-mentioned issues and has developed a system for monitoring a fiber curing tube, comprising: an elliptical reflecting chamber; a collimated light source placed on a first side of the elliptical reflecting chamber, a centerline of the collimated light source offset from a fiber in the elliptical reflecting chamber such that light from the collimated light source does not impinge on the fiber; and a light receiver positioned on a second side of the elliptical reflecting chamber and opposite the collimated light source.
By sensing light from a collimated light source passing through a curing tube, it may be possible to provide a more accurate estimate of curing tube degradation. Further, the collimated light source may be applied in a fiber curing system that includes dual elliptical reflecting chambers that may concentrate light energy more effectively than a single elliptical reflecting chamber. Further still, the collimated light may scatter less than other light sources such that the signal to noise ratio of the detected collimated light may be greater than for other types of light sources.
The present description may provide several advantages. In particular, the approach may provide improve estimates of curing tube degradation. Additionally, the approach may be useful for controlling other portions of a fiber curing system, such as inert gas flow control. Further, the approach may also provide more uniform curing of protective fiber coatings.
The above advantages and other advantages, and features of the present description will be readily apparent from the following Detailed Description when taken alone or in connection with the accompanying drawings.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.